Antibiotic rubomycins were known in medicine heretofore (cf. an article "Physicochemical properties of an antitumor antibiotic Rubomycin produced by Actinomyces coeruleorubidus" by M. G. Brazhnikova, N. V. Konstantinova et al., in a journal "Antibiotiki" (Antibiotics) No. 9, 1966, Meditsina Publishers, Moscow, pp. 763 through 766/in Russian/).
The aforementioned antibiotic is also referred to in international practice as Daunorubicin. Synonyms of rubomycin are also Daunomycin and Rubidomycin.
At present rubomycin is in widespread clinical use for treatment of acute leukoses, chorionepithelioma of the uterus, and tumoral reticulosis (cf. "Clinical chemotherapy of neoplastic diseases" by N. I. Perevodchikova, issued in 1976 by Meditsina Publishers, Moscow, p.37/in Russian/).
However, rubomycin produces also various untoward effects, viz., it is cardiotoxic, inhibits hemopoiesis, has but a restricted range of action and inadequate antitumor activity.
There are also known some rubomycin derivatives, i.e., substituted hydrazones of daunorubicin (rubomycin) of the following general formula ##STR2## where R is COCH.sub.3, COC.sub.2 H.sub.5, COCH(CH.sub.3).sub.2, CO(CH.sub.2).sub.14 CH.sub.3, COC.sub.6 H.sub.5, COC.sub.6 H.sub.4 N, COC.sub.6 H.sub.4 (-pOCH.sub.3), or CHO, said derivatives featuring antitumor activity.
The majority of these compounds retains the activity of daunorubicin, some of them being less toxic than the latter. The best among these compounds proves to be daunorubicin benzoylhydrazone (rubidazone, where R is COC.sub.6 H.sub.5), which is less cardiotoxic (cf. French Pat. No. 1,578,722 published in 1967, Class CO7d).